# CVE-2025-12390: Org.keycloak.protocol.oidc.endpoints.logoutendpoint: offline session takeover due to reused authentication session id

> Attackers can hijack user sessions by exploiting reused authentication session IDs during logout, leading to unauthorized access to another user's account.

- **Severity:** Medium 6.0 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 28 Oct 2025
- **Updated:** 30 Jul 2026
- **Also known as:** ECHO-c70d-0dfc-e7d7, GHSA-rg35-5v25-mqvp, MINI-3mx9-5g5m-mf9x, MINI-r2p7-f2gx-7gh6

## What is CVE-2025-12390?

CVE-2025-12390 is a medium-severity authentication bypass vulnerability in Red Hat build of Keycloak 26.2, published on 28 Oct 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A flaw was found in Keycloak. In Keycloak where a user can accidentally get access to another user's session if both use the same device and browser. This happens because Keycloak sometimes reuses session identifiers and doesn’t clean up properly during logout when browser cookies are missing. As a result, one user may receive tokens that belong to another user.

Weakness: CWE-384 (Session Fixation)

## Which versions are affected by CVE-2025-12390?

2 open source packages ship an affected version, including org.keycloak:keycloak-services.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.keycloak:keycloak-services` | Maven | All versions | 26.0.0 |
| `org.keycloak:keycloak-services` | Maven | All versions | 26.0.0 |

## How do I fix CVE-2025-12390?

Upgrade org.keycloak:keycloak-services to 26.0.0 or later.

## Is CVE-2025-12390 being exploited?

There is no known exploitation of CVE-2025-12390 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-12390 and fix it if it is affected.

What it is: CVE-2025-12390 is a medium-severity authentication bypass vulnerability in Red Hat build of Keycloak 26.2, published on 28 Oct 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-12390 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.keycloak:keycloak-services (Maven): affected all versions; fixed in 26.0.0
- org.keycloak:keycloak-services (Maven): affected all versions; fixed in 26.0.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-12390/ (Markdown: https://insights.sbomify.com/CVE-2025-12390/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-12390
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-12390
- OSV: https://osv.dev/vulnerability/CVE-2025-12390

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-12390/
Summaries are generated and may contain mistakes; the official description above is the record.